list.java

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/* List.java -- A listbox widget
   Copyright (C) 1999, 2002 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package java.awt;

import java.io.Serializable;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.peer.ListPeer;
import java.awt.peer.ComponentPeer;
import java.util.Vector;
import javax.accessibility.Accessible;

/**
  * Class that implements a listbox widget
  *
  * @author Aaron M. Renn ([e-mail])
  */
public class List extends Component
  implements ItemSelectable, Serializable, Accessible
{

/*
 * Static Variables
 */

// Serialization constant
private static final long serialVersionUID = -3304312411574666869L;

/*************************************************************************/

/*
 * Instance Variables
 */

// FIXME: Need read/writeObject

/**
  * @serial The items in the list.
  */
private Vector items = new Vector();

/**
  * @serial Indicates whether or not multiple items can be selected
  * simultaneously.
  */
private boolean multipleMode;

/**
  * @serial The number of rows in the list.  This is set on creation
  * only and cannot be modified.
  */
private int rows;

/**
  * @serial An array of the item indices that are selected.
  */
private int[] selected;

/**
  * @serial An index value used by <code>makeVisible()</code> and
  * <code>getVisibleIndex</code>.
  */
private int visibleIndex;

// The list of ItemListeners for this object.
private ItemListener item_listeners;

// The list of ActionListeners for this object.
private ActionListener action_listeners;

/*************************************************************************/

/*
 * Constructors
 */

/**
  * Initializes a new instance of <code>List</code> with no visible lines
  * and multi-select disabled.
  *
  * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  */
public
List()
{
  this(4, false);
}

/*************************************************************************/

/**
  * Initializes a new instance of <code>List</code> with the specified
  * number of visible lines and multi-select disabled.
  *
  * @param lines The number of visible lines in the list.
  *
  * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  */
public
List(int rows)
{
  this(rows, false);
}

/*************************************************************************/

/**
  * Initializes a new instance of <code>List</code> with the specified
  * number of lines and the specified multi-select setting.
  *
  * @param lines The number of visible lines in the list.
  * @param multipleMode <code>true</code> if multiple lines can be selected
  * simultaneously, <code>false</code> otherwise.
  *
  * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.
  */
public 
List(int rows, boolean multipleMode)
{
  this.rows = rows;
  this.multipleMode = multipleMode;

  if (GraphicsEnvironment.isHeadless())
    throw new HeadlessException ();
}

/*************************************************************************/

/*
 * Instance Variables
 */

/**
  * Returns the number of items in this list.
  *
  * @return The number of items in this list.
  */
public int
getItemCount()
{
  return(items.size());
}

/*************************************************************************/

/**
  * Returns the number of items in this list.
  *
  * @return The number of items in this list.
  *
  * @deprecated This method is deprecated in favor of
  * <code>getItemCount()</code>
  */
public int
countItems()
{
  return(getItemCount());
}

/*************************************************************************/

/**
  * Returns the complete list of items.
  *
  * @return The complete list of items in the list.
  */
public synchronized String[]
getItems()
{
  String[] l_items = new String[getItemCount()];
 
  items.copyInto(l_items);
  return(l_items);
}

/*************************************************************************/

/**
  * Returns the item at the specified index.
  *
  * @param index The index of the item to retrieve.
  *
  * @exception IndexOutOfBoundsException If the index value is not valid.
  */
public String
getItem(int index)
{
  return((String)items.elementAt(index));
}

/*************************************************************************/

/**
  * Returns the number of visible rows in the list.
  *
  * @return The number of visible rows in the list.
  */
public int
getRows()
{
  return(rows);
}

/*************************************************************************/

/**
  * Tests whether or not multi-select mode is enabled.
  *
  * @return <code>true</code> if multi-select mode is enabled,
  * <code>false</code> otherwise.
  */
public boolean
isMultipleMode()
{
  return(multipleMode);
}

/*************************************************************************/

/**
  * Tests whether or not multi-select mode is enabled.
  *
  * @return <code>true</code> if multi-select mode is enabled,
  * <code>false</code> otherwise.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>isMultipleMode()</code>.
  */
public boolean
allowsMultipleSelections()
{
  return(multipleMode);
}

/*************************************************************************/

/**
  * This method enables or disables multiple selection mode for this
  * list.
  *
  * @param multipleMode <code>true</code> to enable multiple mode,
  * <code>false</code> otherwise.
  */
public void
setMultipleMode(boolean multipleMode)
{
  this.multipleMode = multipleMode;
  if (peer != null)
    {
      ListPeer l = (ListPeer) peer;
      l.setMultipleMode (multipleMode);
    }
}

/*************************************************************************/

/**
  * This method enables or disables multiple selection mode for this
  * list.
  *
  * @param multipleMode <code>true</code> to enable multiple mode,
  * <code>false</code> otherwise.
  */
public void
setMultipleSelections(boolean multipleMode)
{
  setMultipleMode(multipleMode);
}

/*************************************************************************/

/**
  * Returns the minimum size of this component.
  *
  * @return The minimum size of this component.
  */
public Dimension
getMinimumSize()
{
  return(getMinimumSize(rows));
}

/*************************************************************************/

/**
  * Returns the minimum size of this component.
  *
  * @return The minimum size of this component.
  *
  * @deprecated This method is deprecated in favor of
  * <code>getMinimumSize</code>.
  */
public Dimension
minimumSize()
{
  return(getMinimumSize(rows));
}

/*************************************************************************/

/**
  * Returns the minimum size of this component assuming it had the specified
  * number of rows.
  *
  * @param rows The number of rows to size for.
  *
  * @return The minimum size of this component.
  */
public Dimension
getMinimumSize(int rows)
{
  ListPeer lp = (ListPeer)getPeer();
  if (lp != null)
    return(lp.minimumSize(rows));
  else
    return(new Dimension(0,0));
}

/*************************************************************************/

/**
  * Returns the minimum size of this component assuming it had the specified
  * number of rows.
  *
  * @param rows The number of rows to size for.
  *
  * @return The minimum size of this component.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>getMinimumSize(int)</code>>
  */
public Dimension
minimumSize(int rows)
{
  return(getMinimumSize(rows));
}

/*************************************************************************/

/**
  * Returns the preferred size of this component.
  *
  * @return The preferred size of this component.
  */
public Dimension
getPreferredSize()
{
  return(getPreferredSize(rows));
}

/*************************************************************************/

/**
  * Returns the preferred size of this component.
  *
  * @return The preferred size of this component.
  *
  * @deprecated This method is deprecated in favor of
  * <code>getPreferredSize</code>.
  */
public Dimension
preferredSize()
{
  return(getPreferredSize(rows));
}

/*************************************************************************/

/**
  * Returns the preferred size of this component assuming it had the specified
  * number of rows.
  *
  * @param rows The number of rows to size for.
  *
  * @return The preferred size of this component.
  */
public Dimension
getPreferredSize(int rows)
{
  ListPeer lp = (ListPeer)getPeer();
  if (lp != null)
    return(lp.preferredSize(rows));
  else
    return(new Dimension(0,0));
}

/*************************************************************************/

/**
  * Returns the preferred size of this component assuming it had the specified
  * number of rows.
  *
  * @param rows The number of rows to size for.
  *
  * @return The preferred size of this component.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>getPreferredSize(int)</code>>
  */
public Dimension
preferredSize(int rows)
{
  return(getPreferredSize(rows));
}

/*************************************************************************/

/**
  * This method adds the specified item to the end of the list.
  *
  * @param item The item to add to the list.
  */
public void
add(String item)
{
  add(item, -1);
}

/*************************************************************************/

/**
  * This method adds the specified item to the end of the list.
  *
  * @param item The item to add to the list.
  *
  * @deprecated Use add() instead.
  */
public void
addItem(String item)
{
  addItem(item, -1);
}

/*************************************************************************/

/**
  * Adds the specified item to the specified location in the list.
  * If the desired index is -1 or greater than the number of rows
  * in the list, then the item is added to the end.
  *
  * @param item The item to add to the list.
  * @param index The location in the list to add the item, or -1 to add
  * to the end.
  */
public void
add(String item, int index)
{
  if ((index == -1) || (index >= items.size()))
    items.addElement(item);
  else
    items.insertElementAt(item, index);

  if (peer != null)
    {
      ListPeer l = (ListPeer) peer;
      l.add (item, index);
    }
}

/*************************************************************************/

/**
  * Adds the specified item to the specified location in the list.
  * If the desired index is -1 or greater than the number of rows
  * in the list, then the item is added to the end.
  *
  * @param item The item to add to the list.
  * @param index The location in the list to add the item, or -1 to add
  * to the end.
  *
  * @deprecated Use add() instead.
  */
public void
addItem(String item, int index)
{
  add(item, index);
}

/*************************************************************************/